A pipe anchor or helical or screw pile is used as a building foundation. The helical pile is driven into the ground and carries the structure's load. Helical bearing plates connected to the shaft of the helical pile transfer the load to the soil. A drive tool connects the helical pile to a powered drive head to drive the helical pile into the ground.
Fastener holes are disposed at ends of members of a helical pile system to facilitate connecting adjacent members together. Fasteners are inserted radially through the fastener holes to secure the adjacent members together. Thus, tension, compression and torque of the helical pile system is transferred from one member to an adjacent member is transferred solely through the fasteners. The fasteners limit the amount of torque that can be transferred through the helical pile system. Accordingly, a need exists for a coupling assembly in which an increased amount of torque can be transferred through a helical pile system.
Another disadvantage of such coupling is the difficulty associated with aligning the fastener holes such that fasteners can be inserted therein. The helical pile system members can be large and unwieldy, increasing the difficulty of aligning the fastener holes. Additionally, the helical pile system members can have circular cross sections, further increasing alignment difficulty. The lack of a stop member in helical pile system members increases the difficulty of bringing the two members together for alignment. Accordingly, a need exists for a coupling assembly in which helical pile system members are quickly and easily aligned and connected.
The fasteners extend radially inwardly, thereby reducing the inner diameter of the helical pile system members. Helical pile systems often have hollow members such that components can extend or be conveyed through the inner diameter of the system. However, the fasteners reduce this inner diameter such that components cannot be extended or conveyed through the hollow members of a helical pile system. Accordingly, a need exists for a coupling assembly in which an inner diameter of members of the helical pile system is not reduced.
The bulky coupling of the helical pile system members using fasteners causes an increased soil disturbance as the helical pile system members are driven through soil. The increased soil disturbance results in larger skin friction, thereby reducing the depth to which the helical pile system can be driven. Accordingly, a need exists for a coupling assembly having a low profile to minimize soil disturbance.